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| | Making the Heart Beat: Dynamic Models of Myocardial Sarcomere Force Generation |
 | | Mechanical models of the heart must describe two levels of mechanical behavior: (1)the supra-molecular biophysical process of force generation by a cardiac sarcomere, and (2)the tissue-level stresses created when such force generators are embedded into a 3D myocardial mechanical matrix. | | | Nevertheless, by using systems-analytical approaches (e.g., impulse response and frequency response), we have phenomenological handles on key dynamic aspects of the relationship between sarcomere length and force. | | | This is the least well understood aspect of cardiac sarcomere dynamics. |
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http://www.physiome.org/files/99symp/abs/hunter.html
(1022 words)
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| | EXCURSION IS IMPORTANT IN REGULATING SARCOMERE NUMBER IN GROWING ANIMALS |
| | The results of this study support the hypothesis that muscle excursion (the change in muscle length required to produce the full range of joint motion) is important in regulating sarcomere number in growing animals. | | | Previous studies have suggested that muscle excursion may be important in regulating sarcomere number in growing animals (2,3). | | | The increase in sarcomere number occurred despite the working length of the muscle being reduced for all but the most plantarflexed positions; decreased working length has been associated with decreased sarcomere number for immobilization experiments using adult muscle (1). |
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http://www.asb-biomech.org/onlineabs/NACOB98/213
(868 words)
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| | sarcomere length stand alone |
| | The device is now being used in experiments where sarcomere length is monitored and controlled in cardiac trabeculae. | | | The Sarcomere length detector (SLD) system was developed for research of cardiac cells. | | | The system had been designed by Dr. Henk ter Keurs to measure sarcomere length in rat cardiac trabeculae. |
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http://www.ucalgary.ca/md/BTSC/slc.htm
(342 words)
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| | 1. The sarcomere |
| | The appearance of the striations change during shortening allowing us to examine the relationship between active force and sarcomere length (see self assessment exercises). | | | Understanding the organisation of striated muscle at the level of the sarcomere and the contractile proteins that give rise to sarcomere striations is crucial if one is to understand how striated muscle functions and to appreciate the important differences between skeletal and cardiac and smooth muscles. | | | A sarcomere from a mammalian muscle is about 2.4 micrometer long at rest. |
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http://bris.ac.uk/Depts/Physiology/ugteach/ugindex/m1_index/nm_tut4/page1.htm
(507 words)
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| | Muscle Biochemistry |
| | During contraction and relaxation the distance between the Z lines varies, decreasing with contraction and increasing with relaxation. | | | Sarcomeres represent the minimal contractile unit of a muscle. | | | Skeletal muscles comprise about 40% of the mass of the average human body and are formed of long multinucleate, cylindrical cells called |
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http://web.indstate.edu/thcme/mwking/muscle.html
(3267 words)
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| | Sarcomere Gene Mutation Screening |
| | Individuals interested in participating in a research study may contact Barbara McDonough, R.N. for more information. | | | patients with sarcomere mutations who have been examined by our lab. | | | Knowledge of this complete set of mutations will provide insights into the mechanisms by which these mutations cause cardiac disease as well as provide useful tools for the genetic diagnoses of these conditions. |
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http://cardiogenomics.med.harvard.edu/project-detail?project_id=230
(642 words)
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| | The educational encyclopedia, muscular system, muscles, anatomy |
| | Muscles in action the muscle actions of the human body | | | Muscle contraction contraction mechanism involves sliding of the thin filaments past the thick ones The myosin heads form cross bridges which link to the actin. | | | Each cross bridge attaches and detaches several times during contraction and so acts like an oar which rows the thin filaments towards the middle of the sarcomere |
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http://users.pandora.be/educypedia/education/muscles.htm
(525 words)
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| | CCP13 publications |
| | Architecture and function in the muscle sarcomere, J.M. Squire, Curr. | | | Architecture and function in the muscle sarcomere Squire, J.M., Biol. | | | "Heterogeneity of Z-band structure within a single muscle sarcomere". |
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http://www.ccp13.ac.uk/publications/publications.htm
(11818 words)
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| | diffractometer, Sarcomere length caliper |
| | This device will provide researchers in the science and industry environment a state-of-the-art tool to assess the mechanical properties of cardiac cells in the study of mechanisms underlying cardiac arrhythmia and in the study of pharmacological and molecular biological means of preventing and treating cardiac arrhythmias. | | | The objective (muscle tissue etc..), to be measured is mounted on the microscope objective plan. | | | m) the muscle fibers behave like an optical grating and hence create a series of small light sources at equi-distances which are phase shifted, the phase shift is proportional to the gap between the light sources (the sarcomeres to be measured). |
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http://www.ucalgary.ca/UofC/faculties/md/BTSC/difractometer.html
(537 words)
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| | IV. Myology. 2. Development of the Muscles. Gray, Henry. 1918. Anatomy of the Human Body. |
| | In muscle there is the same thing, viz., a framework of spongioplasm staining with hematoxylin—the substance of the sarcous element—and this encloses a clear hyaloplasm, the clear substance of the sarcomere, which resists staining with this reagent. | | | A sarcostyle may be said to be made up of successive portions, each of which is termed a sarcomere. | | | The contraction of the muscle is merely the sum total of this widening out and shortening of these bodies. |
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http://www.bartleby.com/107/103.html
(2924 words)
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| | Encyclopedia article on Muscle [EncycloZine] |
| | Muscle is composed of muscle cells (sometimes known as "muscle fibers"). | | | Muscle contraction is used to move parts of the body, as well as to move substances within the body. | | | Muscle cells are bound together by perimysium into bundles called fascicules; the bundles are then grouped together to form muscle, which is lined by epimysium. |
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http://encyclozine.com/Muscle
(986 words)
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| | Sarcomere Contraction |
| | The muscle contraction is a result of the actin and myosin filaments sliding over each other, thereby causing the length of the sarcomere to shorten. | | | On the microscopic level, the muscle contraction occurs through a smaller contraction of the sarcomere. | | | The sarcomere is a functional unit composed of two membranes (Z-lines), which act as boundaries. |
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http://www.unc.edu/~scmannin/greg.html
(72 words)
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| | Muscle Structure & Function: Part 3 |
| | Inside the muscle fibers, the signal stimulates the flow of calcium which causes the thick and thin myofilaments to slide across one another. | | | The sarcomere is the name given to the "unit pattern" that is repeated along the myofibril. | | | When billions of sarcomeres in the muscle shorten all at once it results in a contraction of the entire muscle fiber. |
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http://www.scnf.org/riley3.html
(2875 words)
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| | [No title] |
| | The sarcomere is the structure responsible for muscle contraction, and contains the proteins actin, myosin, titin and telethonin. | | | The borders of individual sarcomeres are the Z-lines, which are precisely aligned and laterally associated with intermediate filament proteins (such as desmin) and other cytoskeletal proteins (such as plectin). | | | Although many of the detailed interactions are not yet known, these linkages are responsible for the mechanical integration and stability of myofibrils, organelles, and membrane components for effective force transmission. |
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http://www.siumed.edu/~eniederhoffer/som_pbl/SSB/musc_bioch/musc_biochem.doc
(1783 words)
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| | Sarcomere |
| | Contraction begins when the myosin is stimulated by a nerve impulse; when stimulated, the globular head of a myosin protein binds with the actin to form actomyosin. | | | As each sarcomere is shortened, the length of each myofibril and fiber is shortened and, thus, the length of the muscle itself is shortened as well. | | | Once bound, the myosin head is able to break ATP into ADP and Pi releasing energy which causes the myosin head to pull the actin toward the center of the sarcomere. |
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http://www.scientia.org/cadonline/Biology/specialcells/sarcomere.ASP
(361 words)
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| | Sarcomere Structure |
| | In skeletal muscle, each sarcomere has two T-tubules, which lie at the junction of the A- and I-bands (located at each end of the myosin filament), and the terminal cisternae, which abut on each side of the T-tubule. | | | Each fiber is composed of myofibrils, which is a series of repeating structural units called sarcomeres arranged end-to-end. | | | A cytoskeleton strengthens the plasma membrane and holds intracellular structures in place. |
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http://www-rohan.sdsu.edu/~ens632/SarcomereStructure.htm
(930 words)
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| | [No title] |
| | Stretching the muscle prior to contraction (adding preload) from point a to c, results in an increase in developed tension (d vs. b). | | | Stretching the muscle optimizes the overlap of myosin and actin filaments thus increasing the number of cross bridges (Figure 12B). | | | Ca++ sparks are also triggered by depolarization when the voltage gated L type Ca++ channel locally increase Ca++ concentration to activate the release channel by Ca++ induced Ca++ release. |
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http://www.med.unc.edu/wrkunits/2depts/pharm/phco202/04camCorBlood.doc
(2570 words)
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| | Skeletal Muscle: Biceps, Fibres, Fibrils and Sarcomeres. |
| | Fiber, H-zone, M-line, Myofibril, Sarcomere, Skeletal muscle, Thick filament, Thin Filment, Z-line | | | With kind permission of Dr. Ludmilla Skubiszak, from the from the Polish Academy of Sciences, Warsaw | | | The structure of the thick filament and M-line (animation) |
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http://lessons.harveyproject.org/development/muscle/strufast.html
(102 words)
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